Past perfect simple and past perfect continuous

I was wondering why the past perfect simple is used in one sentence and the past perfect continuous in the other. What is the difference?

"The bartender looked at the seat the customer had occupied."

The customer left a short time before and he is no longer occupying the seat.

"I picked up and folded the chair I had been occupying."

I am no longer occupying the chair, otherwise I wouldn't be able to pick up and fold it.

Would it be possible to say: The bartender looked at the seat the customer had been occupying?